From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dominik Brodowski Subject: Re: [PATCH 5/5] processor: jiffies-based bm_check Date: Fri, 21 Jan 2005 17:23:36 +0100 Message-ID: <20050121162336.GA8435@dominikbrodowski.de> References: <20041223140849.GE7973@dominikbrodowski.de> <1103832683.4376.24.camel@d845pe> <1106280485.2397.135.camel@d845pe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1106280485.2397.135.camel@d845pe> Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Len Brown Cc: ACPI Developers , Venkatesh Pallipadi , Robert Moore List-Id: linux-acpi@vger.kernel.org On Thu, Jan 20, 2005 at 11:08:06PM -0500, Len Brown wrote: > On Thu, 2004-12-23 at 15:11, Len Brown wrote: > > > Didn't apply the jiffies part yet. > > I've applied it now. (attached as jiffy.patch) > > However, "threshold.bm = 0xF" was written when > HZ = 100 yielding 40ms, but this > becomes 4ms for HZ = 1000. > > While I don't know what the optimal value is for > the bus master history threshold, it seemed like > a good idea for it to default to about 40ms per > the original code until we know better. > > So I've also applied the attached bm_history.patch > to default this to 0xFFFFFFFF for HZ = 1000 (32ms) > and it is tunable via /sys/module/processor/parameters/bm_history > > what do you think? This sounds sensible to do. Note that the "diff" measured in idle() will become problematic once "tickless" systems are implemented -- we'll sleep for multiple jiffies then, and there was _no_ bm activiy in between. We need to sort that out somehow... Dominik ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl